Activation of Trypsinogen and Plasminogen by Thrombin Preparations<sup>*</sup>

Engel, Araceli M.; Alexander, Benjamin; Pechet, Liberto

doi:10.1021/bi00869a014

Cited by 55 publications

(12 citation statements)

References 30 publications

(41 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As in similar studies with trypsinogen and plasminogen (Engel et al, 1966), activation by several different thrombin preparations was compared. These were : (a) citrate thrombin, as described above; (b) thrombin purified by electrophoresis; (c) purified thrombin of' Magnusson; (d) acetylated thrombin; (e) the waterinsoluble thrombin-phenylalanineleucine copolymer.…”

Section: Resultsmentioning

confidence: 99%

Activation of Chymotrypsinogen-A by Thrombin Preparations^*

Engel¹,

Alexander²

1966

Biochemistry

Self Cite

View full text Add to dashboard Cite

Earlier demonstration that thrombin resembles trypsin in the ability to convert trypsinogen and plasminogen to their respective proteases prompted investigation of its effect on chymotrypsinogen A. Purified thrombin added to the zymogen induced rapid and progressive appearance of esterolytic activity toward acetyltyrosyl ethyl ester. The addition of indole to the zymogen-thrombin mixture after interaction had proceeded obviated esterolysis, indicating that the evolved activity was due to chymotrypsin. Elaboration of the active enzyme from its precursor appeared to take place in accord with enzyme kinetics, the thrombin functioning enzymatically on the zymogen. That this was not due to a possible trypsin contaminant of the thrombin was demonstrated with appropriate inhibitors, by procedures known to block thrombic action, and by separation of certain known contaminants, which T hrombin resembles trypsin in many enzymatic properties (Sherry and Troll, 1954; MiUer and Van Vunakis, 1956;Gladner and Laki, 1956; Laki et al., 1958;Martin et al., 1959;Ronwin, 1960;Laki and Gladner, 1964;Sherry et al., 1965; KCzdy et al., 1965), including the ability to activate trypsinogen and plasminogen (Engel et al., 1966). Since cleavage of the ester and peptide bonds of many synthetic substrates (Ehrenpreis et al., 1957;Lorand et al., 1962;Elmore and Curragh, 1963; Baird ef al., 1965) and proteins1 are catalyzed by both enzymes, and since trypsin activates chymotrypsinogen, the question whether thrombin can similarly activate this zymogen was explored.

show abstract

Section: Resultsmentioning

confidence: 99%

Activation of Chymotrypsinogen-A by Thrombin Preparations^*

Engel¹,

Alexander²

1966

Biochemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…If present, this zymogen could be activated by thrombin (73) or enterokinase (74). Thrombin has only been found as the zymogen form in human milk (14), and enterokinase has not been found in either bovine or human milk.…”

Section: Proteolytic Systems In Milkmentioning

confidence: 99%

Proteolytic Systems in Milk: Perspectives on the Evolutionary Function within the Mammary Gland and the Infant

Dallas

Murray

Gan

2015

J Mammary Gland Biol Neoplasia

100

View full text Add to dashboard Cite

Milk contains elements of numerous proteolytic systems (zymogens, active proteases, protease inhibitors and protease activators) produced in part from blood, in part by mammary epithelial cells and in part by immune cell secretion. Researchers have examined milk proteases for decades, as they can cause major defects in milk quality and cheese production. Most previous research has examined these proteases with the aim to eliminate or control their actions. However, our recent peptidomics research demonstrates that these milk proteases produce specific peptides in healthy milk and continue to function within the infant’s gastrointestinal tract. These findings suggest that milk proteases have an evolutionary function in aiding the infant’s digestion or releasing functional peptides. In other words, the mother provides the infant with not only dietary proteins but also the means to digest them. However, proteolysis in the milk is controlled by a balance of protease inhibitors and protease activators so that only a small portion of milk proteins are digested within the mammary gland. This regulation presents a question: If proteolysis is beneficial to the infant, what benefits are gained by preventing complete proteolysis through the presence of protease inhibitors? In addition to summarizing what is known about milk proteolytic systems, we explore possible evolutionary explanations for this proteolytic balance.

show abstract

“…There are other serine proteases like thrombin [30], F XII [31] and trypsin [32], that could, under certain circumstances, activate plasminogen to plasmin, supplementing the diminished fibrinolytic activity. Nevertheless, in the cases reported here, none of these alternative pathways of activation seemed to provide the active enzyme probably due to the increased amount of the inhibitor of plasminogen activation.…”

Section: Discussionmentioning

confidence: 99%

Natural Inhibitors and Fibrinogen/Fibrin Degradation Products in Patients with Myocardial Infarction

Engel¹,

Finkelstein²

1981

Pathophysiol Haemos Thromb

View full text Add to dashboard Cite

The activity of the inhibitor of activated Stuart factor (anti-X_a) was evaluated together with the activity of the antiactivator of plasminogen (antiplasminogen) and the amount and nature of the fibrinogen/fibrin degradation products (FDP), as indicators of the existence of the risk for hypercoagulability in patients with acute and recent myocardial infarction (AMI and RMI, respectively). The activity of anti-X_a was diminished in the AMI group with a p < 0.001. The antiplasminogen activity was increased in both groups with a p < 0.001; on the other hand, the amount of FDP was increased in the AMI patients and they were of the ‘early’ type, while in the RMI group the increase was not as marked, but the FDP were of the ‘late’ type. In both groups the euglobulin lysis time was very prolonged, while the plasminogen did not vary significantly. The tests described appear to be valuable tools for studying the status of the cardiovascular system during cardiac rehabilitation.

show abstract

Activation of Trypsinogen and Plasminogen by Thrombin Preparations^*

Cited by 55 publications

References 30 publications

Activation of Chymotrypsinogen-A by Thrombin Preparations^*

Activation of Chymotrypsinogen-A by Thrombin Preparations^*

Proteolytic Systems in Milk: Perspectives on the Evolutionary Function within the Mammary Gland and the Infant

Natural Inhibitors and Fibrinogen/Fibrin Degradation Products in Patients with Myocardial Infarction

Contact Info

Product

Resources

About

Activation of Trypsinogen and Plasminogen by Thrombin Preparations*

Cited by 55 publications

References 30 publications

Activation of Chymotrypsinogen-A by Thrombin Preparations*

Activation of Chymotrypsinogen-A by Thrombin Preparations*

Proteolytic Systems in Milk: Perspectives on the Evolutionary Function within the Mammary Gland and the Infant

Natural Inhibitors and Fibrinogen/Fibrin Degradation Products in Patients with Myocardial Infarction

Contact Info

Product

Resources

About

Activation of Trypsinogen and Plasminogen by Thrombin Preparations^*

Activation of Chymotrypsinogen-A by Thrombin Preparations^*

Activation of Chymotrypsinogen-A by Thrombin Preparations^*